Dirofilariasis in a 22-year-old airman deployed to the Mediterranean

A 22-year-old male U.S. Navy airman with new nontender subcutaneous, 4-cm mass inferior to the right anterior costal margin was sent for routine biopsy. Sudden appearance of axillary lymph nodes prompted immediate excisional biopsy of the primary mass. Pathological evaluation was initially read as Onchocerca volvulus, the filarial nematode classically responsible for river blindness. Subsequent evaluation by Armed Forces Institute of Pathology resulted in a change of diagnosis to Dirofilaria species, not pathogenic in humans. The author discusses the literature of Dirofilaria infestations in humans, and how they may affect U.S. servicemen and women traveling to endemic areas.